SEAL MEMBER, STEAM TURBINE, AND METHOD OF AVOIDING RESONANCE

摘要

A first seal member 21A according to a first embodiment of the present invention includes a double-structure bellows 22 in corrugated form, and vibration control means provided on the outside of the bellows 22 such as to cover part of the bellows 22. A flat portion 23 that is not in corrugated form is provided in part of the bellows 22. The vibration control means is provided in a circumferential direction on an outer surface of the flat portion 23, and made up of a ring-shaped rib 25 having a plurality of holes in a circumferential direction and weights 26 inserted in the holes provided in an outer wall of the rib 25. Natural frequency is adjusted by adjusting the number of weights 26, thereby preventing resonance between the natural frequency of the first seal member 21A and the rotational frequency of a rotor from occurring.